/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.metrics.config;

import org.apache.iotdb.metrics.utils.InternalReporterType;
import org.apache.iotdb.metrics.utils.MetricFrameType;
import org.apache.iotdb.metrics.utils.MetricLevel;
import org.apache.iotdb.metrics.utils.ReporterType;

import java.util.Properties;
import java.util.stream.Collectors;

/**
 * The utils class to load properties
 */
public class MetricConfigDescriptor {
    /**
     * The metric config of metric service
     */
    private final MetricConfig metricConfig;

    private MetricConfigDescriptor() {
        metricConfig = new MetricConfig();
    }

    /**
     * Load properties into metric config
     */
    public void loadProps(Properties properties) {
        MetricConfig loadConfig = generateFromProperties(properties);
        metricConfig.copy(loadConfig);
    }

    /**
     * Load properties into metric config when reload service.
     *
     * @return reload level of metric service
     */
    public ReloadLevel loadHotProps(Properties properties) {
        MetricConfig newMetricConfig = generateFromProperties(properties);
        ReloadLevel reloadLevel = ReloadLevel.NOTHING;
        if (!metricConfig.equals(newMetricConfig)) {
            if (!metricConfig.getMetricFrameType().equals(newMetricConfig.getMetricFrameType())
                    || !metricConfig.getMetricLevel().equals(newMetricConfig.getMetricLevel())
                    || !metricConfig
                    .getAsyncCollectPeriodInSecond()
                    .equals(newMetricConfig.getAsyncCollectPeriodInSecond())) {
                // restart metric service
                reloadLevel = ReloadLevel.RESTART_METRIC;
            } else if (!metricConfig
                    .getInternalReportType()
                    .equals(newMetricConfig.getInternalReportType())) {
                // restart internal reporter
                reloadLevel = ReloadLevel.RESTART_INTERNAL_REPORTER;
            } else {
                // restart reporters
                reloadLevel = ReloadLevel.RESTART_REPORTER;
            }
            metricConfig.copy(newMetricConfig);
        }
        return reloadLevel;
    }

    /**
     * Load properties into metric config
     */
    private MetricConfig generateFromProperties(Properties properties) {
        MetricConfig loadConfig = new MetricConfig();

        String reporterList =
                getProperty(
                        "metric_reporter_list",
                        String.join(
                                ",",
                                loadConfig.getMetricReporterList().stream()
                                        .map(ReporterType::toString)
                                        .collect(Collectors.toSet())),
                        properties);
        loadConfig.setMetricReporterList(reporterList);

        loadConfig.setMetricFrameType(
                MetricFrameType.valueOf(
                        getProperty(
                                "metric_frame_type", String.valueOf(loadConfig.getMetricFrameType()), properties)));

        loadConfig.setMetricLevel(
                MetricLevel.valueOf(
                        getProperty("metric_level", String.valueOf(loadConfig.getMetricLevel()), properties)));

        loadConfig.setAsyncCollectPeriodInSecond(
                Integer.parseInt(
                        getProperty(
                                "metric_async_collect_period",
                                String.valueOf(loadConfig.getAsyncCollectPeriodInSecond()),
                                properties)));

        loadConfig.setPrometheusReporterPort(
                Integer.parseInt(
                        getProperty(
                                "metric_prometheus_reporter_port",
                                String.valueOf(loadConfig.getPrometheusReporterPort()),
                                properties)));

        MetricConfig.IoTDBReporterConfig reporterConfig = loadConfig.getIoTDBReporterConfig();
        reporterConfig.setHost(
                getProperty("metric_iotdb_reporter_host", reporterConfig.getHost(), properties));

        reporterConfig.setPort(
                Integer.valueOf(
                        getProperty(
                                "metric_iotdb_reporter_port",
                                String.valueOf(reporterConfig.getPort()),
                                properties)));

        reporterConfig.setUsername(
                getProperty("metric_iotdb_reporter_username", reporterConfig.getUsername(), properties));

        reporterConfig.setPassword(
                getProperty("metric_iotdb_reporter_password", reporterConfig.getPassword(), properties));

        reporterConfig.setMaxConnectionNumber(
                Integer.valueOf(
                        getProperty(
                                "metric_iotdb_reporter_max_connection_number",
                                String.valueOf(reporterConfig.getMaxConnectionNumber()),
                                properties)));

        reporterConfig.setLocation(
                getProperty("metric_iotdb_reporter_location", reporterConfig.getLocation(), properties));

        reporterConfig.setPushPeriodInSecond(
                Integer.valueOf(
                        getProperty(
                                "metric_iotdb_reporter_push_period",
                                String.valueOf(reporterConfig.getPushPeriodInSecond()),
                                properties)));

        loadConfig.setInternalReportType(
                InternalReporterType.valueOf(
                        properties.getProperty(
                                "dn_metric_internal_reporter_type",
                                loadConfig.getInternalReportType().toString())));

        return loadConfig;
    }

    /**
     * Get property from confignode or datanode
     */
    private String getProperty(String target, String defaultValue, Properties properties) {
        return properties.getProperty(
                "dn_" + target, properties.getProperty("cn_" + target, defaultValue));
    }

    private static class MetricConfigDescriptorHolder {
        private static final MetricConfigDescriptor INSTANCE = new MetricConfigDescriptor();
    }

    public static MetricConfigDescriptor getInstance() {
        return MetricConfigDescriptorHolder.INSTANCE;
    }

    public MetricConfig getMetricConfig() {
        return metricConfig;
    }
}
